seems like the cheap ones have a problem with noise or coloring the sound, and i just dont know where to look for a quality one. what are some middle of the road, noise/lagless, and sturdy ones (i care a little less about tone sucking because i figure i can just adjust the controls for whatever frequency is lost)?

just for background info, im looking at getting the a/b box for an amp that hasnt arrived yet (the rivera m60). it has two inputs, high and low gain, so i thought an a/b box could work for getting even more different sounds. is this even a good idea? also, if i got an a/b/y box and accidently pressed the y button, making two signals go into the amp, would that kill something?